[Ciliary transition zone of the orthonectid Intoshia variabili].

The ciliary transition zone is described in the orthonectid Intoshia variabili. The ciliary transition zone in this species corresponds to the long type of transition zones. Close proximity of orthonectids to Spiralia is discussed.

[Symmetry of orthonectids and dicyemids].

The analysis of the general structure of orthonectids shows that free-living sexual specimens are bilaterial, while the parasitic plasmodium is anaxonic. All worm-like stages in the life cycle of dicyemids are characterized by monaxonic heteropolar symmetry, while their infusorioform is bilaterial.